海口市城郊蔬菜基地重金属含量分布与评价

Distribution and Evaluation of Heavy Metal Content in Suburban Vegetable Base of Haikou Province

采集了海口市城郊3大蔬菜基地8种叶菜类蔬菜共153个代表样及其相应的根系土样品,以土壤环境质量标准(GB15618-1995)和食品安全标准(GB2762-2012)为土壤和蔬菜中重金属限量标准,用Nemerow综合污染指数和Hakanson潜在生态指数2种评价方法对其进行了评价。结果表明,基地土壤的重金属有效性不大,属于安全、轻微生态危害水平,但Cd的生物潜在有效性较高,对农作物污染风险大。蔬菜对土壤中重金属的富集能力大小为Zn>Cd>Cu>Hg>As>Pb>Cr。所有蔬菜样品中的重金属含量除了Cd外均无超标,其中旱菜Cd超标最严重,超标率达70%,超标倍数最高为0.21。

This paper evaluated 153 representative samples and their corresponding root soil from eight kinds of leafy vegetables in three suburban vegetable bases of Haikou city by soil environmental quality standard and food safety standard （e.g. GB 15618-1995 and GB 2762-2012） and nemerow synthetic pollution index and hakanson potential ecological index as evaluation methods. The results showed that the heavy metal availability was not obvious, the base soil was safe and it had lower ecological hazard level. However, the potential bioavailability of cadmium was clear and it had a high risk factor for crop contamination. The enrichment capability of vegetable to soil heavy metal was Zn〉Cd〉Cu〉Hg〉As〉Pb〉Cr. All heavy metals content were within the safety standard except cadmium in vegetable samples. The exceed ratio of Rorippa was 70%and exceed multiple reached 0.21.